Emerald Ash Borer Approaching Colorado
Due to recent media coverage, there is an increased awareness in Colorado about the threat of Emerald Ash Borer. First and foremost, don’t panic – as far as we know EAB has yet to reach our state. There are traps across Colorado used to monitor the situation and as soon as we hear anything different, we’ll update you.
It is estimated that fifteen percent of the front-range urban forest is made up of ash. These ash trees include both green and white (autumn purple) ash. The closest known infestation is in Kansas City, Kansas which is about 600 miles from the Front Range. It is unknown when the emerald ash borer will reach Colorado. The uncertainty exists because the insect will have to be brought accidentally to Colorado. There is no way the insect will reach us on its own, however we believe it is only a matter of time until it arrives.
The emerald ash borer (EAB) is a relative (same genus) of the bronze birch borer and honeylocust borer. Its life cycle is similar; however the ash borer is much more aggressive – killing the infested tree within a few years. Whereas other boring insects prey upon stressed or weakened trees, the emerald ash borer successfully attacks ALL ash trees in its path. In the upper mid-west and eastern states likely hundreds of millions of infested trees have died.
Emerald ash borer is different from the lilac ash borer which we are familiar with. These two borers feed in the tree differently and have a different life cycle. The control for one borer is not effective for the other.
In anticipation of EAB arriving in Colorado, many municipalities are discouraging or prohibiting the planting of ash trees along city rights-of-ways. Federal, state, and local entities are actively looking for the emerald ash borer.
Can Emerald Ash Borer Be Stopped?
The insect cannot be stopped; rather it can be controlled on individual trees. Early on, attempts were made to eradicate the insect in the mid-west, but these efforts were unsuccessful. Insecticides have been researched, labeled for use and found to be highly successful in protecting individually treated trees.
Currently, we are NOT recommending control treatment for the Emerald Ash Borer.
The insect is not known in Colorado. While destructive, the insect moves slowly. With the heightened awareness, many are on the lookout for EAB for a possible early detection. Government officials are advising against any insecticide control measures at this time.
What Can You Do Now?
Emerald ash borer attacks both healthy and unhealthy trees. However, an unhealthy tree is much less likely (or unlikely) to be able to survive attack. Unlike the lilac ash borer, ALL Emerald Ash Borer treatment strategies involve systemic insecticides. There are no sprays that have been found to be effective controls for EAB. We will be relying upon a systemic insecticide to be taken up by the sap stream of the tree. Weakened, dead and damaged branches will take up little to no insecticide and thus will not be protected by treatment.
In April 2013, sub-freezing temperatures froze twigs and foliage of ash trees at least once and in many cases twice. This has left ash trees in poor condition with many dead branches. We recommend dead branches should be pruned by a local Denver tree pruning company to ensure the best results.
With the dead and weakened branches from the freeze, the lilac ash borer is much more prevalent. Lilac ash borer preys upon weakened trees and those that are less than 20 feet tall. These trees should be protected against the lilac ash borer. Also, a lesser known insect, the ash twig beetle is more widespread this year due to the April freeze damage. Twig beetles should also be controlled if the tree is being attacked.
Give us a call or fill out an online quote form and we’ll have a Landscape Care Consultant evaluate your ash trees to determine if they should be pruned and if insect control is warranted to increase the health of the tree, decreasing the risk of losing it to the Emerald Ash Borer.